The invention records the time-of-day when an item of merchandise is selected by a shopper. The recordation prevents confusion to the shopper when Electronic Price Labels, EPLs, are used to indicate the price. The indicated price can change after the customer selects the item, but before purchase. In such a case, the customer would have seen one price, but be charged another.
Electronic Price Labels, EPLs, are coming into widespread usage in supermarkets and other retail outlets. FIG. 1 illustrates a simplified view of shelves 3 in a supermarket. The shelves 3 carry EPLs 6. A different EPL can be associated with each group of items contained on the shelves. For example, Brand X of tomato sauce would be associated with one EPL, and Brand Y with another EPL. However, the individual jars of Brand X tomato sauce are not associated with individual EPLs: a single EPL represents all Brand X jars.
The EPLs act as miniature electronic displays, and display the prices of the items with which they are associated. For example, the inset EPL 6A displays the price of xe2x80x9c$1.49.xe2x80x9d EPLs can take the form of Liquid Crystal Displays, LCDs; displays using Light Emitting Diodes, LEDs; or can implement other technologies.
The EPLs 6 are controlled by server 9, through one, or more, data channels indicated by bus 12. Historically, in many early EPLs, bus 12 took the form of a hard-wired, physical bus. Today, hard-wired busses are being supplanted by wireless infrastructures, using rf and infra-red communication links. Both wireless and hard-wired systems can utilize the invention.
As an example of operation, the server 9 is given a data file 14, which contains (1) a list of all products carried by the shelves 3, (2) the bus-address of the EPL 6 associated with each product, and (3) a price to be displayed on each EPL 6.
To load a price into each EPL, the server 9, for each item on the list, places the bus-address of an EPL onto the bus 12. The EPLs contain decoding circuits, not shown but known in the art, which read that address. Only the EPL corresponding to the address placed on the bus 12 responds with an acknowledgement.
When the server 9 receives acknowledgement, it transmits the price onto the bus 12. When the EPL receives the price, it latches it, and issues a second, final, acknowledgement. The server 9 then proceeds through the remainder of EPLs on the list, in a similar manner.
Of course, other protocols can be undertaken in controlling and loading the EPLs.
A problem can arise in certain situations, when the supermarket wishes to change the prices displayed by the EPLs. Ordinarily, if the supermarket closes for business at night, it can change the EPLs at that time, and no problem arises. However, if the supermarket does not close, but remains open constantly, the following problem can occur.
A customer can view a price displayed on one of the EPLs 6 in FIG. 2. The customer can select the corresponding item (not shown), and proceed to a check-out station 25. A scanner (not shown) at the check-out station 25 scans the item, and ascertains the price from a Price Look Up table PLU, which is maintained by a system of servers 125.
If the price displayed by the EPL had changed between (1) the time the customer selected the item and (2) the time of check-out, the PLU will contain the new, changed price. If the customer is charged the new price, the customer may become annoyed, because the price actually charged did not match the price displayed by the EPL.
One solution to this problem is to introduce a time delay, as suggested by U.S. Pat. No. 5,988,498 to Hoell, which is assigned to NCR Corporation, to which the present invention is also assigned. This Hoell patent is hereby incorporated by reference.
In Hoell, when a price change is to occur, the change is first made on an EPL 6. However, the change is not implemented immediately at the check-out stations 25. A delay is imposed. The delay is sufficiently long that any affected items will be purchased at the old price, as opposed to the new price.
However, this approach is not perfect. To be perfect, as a minimum, different delays must apply to different customers. For example, assume that a customer selects an item at 12:00, and the delay used is 1 hour. If the EPL changes at 12:15, the customer must check out by 1:15. Otherwise, the customer will be charged the new price. The delay has failed in this instance.
In addition, if a second customer selects the item in question at 12:45, and checks out at 12:50, that customer will be charged the old price, because the new price does not become effective until 1:15. Yet the new price was displayed.
In one form of the invention, whenever a customer selects an item of merchandise from its display point, the time-of-day when the selection occurred is recorded. In another form of the invention, when the customer presents the item at a Point of Sale terminal, POS, the POS uses (1) the time-of-day and (2) a table which states the price displayed at all relevant times, to ascertain the price displayed when the customer selected the item.